Is your feature request related to a problem? Please describe.

Currently RegisterWorkflow and RegisterActivity do not support custom naming. All names are inferred from the function name.
This is complicated because it forces a certain pattern of code organization (e.g. two different packages can not register the same Workflow/Activity if the function name is the same). This also do not allow for patterns like Workflow and Activities factories.

Describe the solution you'd like

To be able to register anonymous functions with custom names.

e.g.

RegisterWorkflow(myfunc, "RegisterUserWorkflow")

Describe alternatives you've considered

Additional context